Category Archives: Gastro

Inflammatory Bowel Disease

Gastro, General paediatrics

Refer under 16s to Paed gastro. Patients prefer cf adult services!

Microbiome pivotal to development of IBD (among other things, eg allergy).  Plus genetic factors – first degree relatives of Crohn’s patients have up to 35x greater risk!  When risk assessed on basis of genotype and smoking, 32% of apparently asymptomatic had evidence of small bowel inflammation (and quite a few had moderate-severe inflammation).

In this study calprotectin over 150microg/g was 95% specific for inflammation (32.6% sensitive). [Poster 2016]

Higher calprotectin in relatives correlates with dysbiosis (ie lower microbial diversity and shifts in composition, including more enterobacteriaceae). [Cell Molec Gastroenterol Hepatol. 2016 Jul 4. doi: 10.1016/j.jcmgh.2016.06.004]

Pathology is leaky tight junctions, innate and adaptive immunity defects.

Types:

  • Crohns  – transmural, skip lesions, mouth to anus.  70% have granulomas.
  • Ulcerative colitis – always involves anorectal region, continuous, more superificial
  • IBDU (undifferentiated)- mucosal only, colon only (cf rectal in UC).  Some evolve into more typical Crohns or UC.

Still rising incidence of Crohns in Scotland (5x in 34 years)!

Presentation

Abdominal pain, diarrhoea (esp bloody), weight loss.  Nocturnal stooling.

Small bowel IBD can present like anorexia nervosa!

Acute/chronic “appendicitis” = terminal ileum Crohns.

Drop in height centile can precede gut symptoms.

Clinical Features

  • Cobblestoning of oral mucosa, buccal tags
  • Swollen joints,
  • Erythema nodosum,
  • Anal fissures or tags.
  • Growth parameters.
  • Ileocaecal mass.
  • Pyoderma gangrenosum is a rare association.

Investigations

Calprotectin is a neutrophil protein.  False pos in infection, polyps, under 5s.  Reduces endoscopy rate by 35%, and earlier diagnosis for some.

200-250 is starting to get specific.  Don’t do under 5yrs!

MR better detail, less radiation for small bowel.  But low availability and expertise.

Treatment

2016 BSPGHAN ArchDisChild guidelines. 

Emphasis on mucosal healing, not just symptoms eg bloods, calprotectin, imaging.

Crohn’s disease

Exclusive nutritional mx 6-8/52 is preferred for active luminal Crohns, mucosal healing better cf steroids.  Microbiome changes, but not to normal!

Solid food version of Modulen being developed.

Early Azathioprine for maintenance.  (Mercaptopurine more appropriate for young children).  Check TPMT enzyme activity to avoid toxicity, start full dose rather than titrating up (2mg/kg unless enzyme pos).  Check metabolite levels if poor response or side effects. Using “discordant metabolites” (6TG, 6MP) benefit from split dosing.

MTX for failed aza (preferred if arthritis).

Surgery good for local disease – no need to fail medical!

Weighted paed CD activity index (wPCDAI) – app available!  PUCAI app not strictly legal…

Anti-TNF treatment – occ non-responders, check levels first!  First line in US, similar to rheumatology: use best Rx first!  Biosimilars available now, cheaper but more complex to make so higher risk of reactions?  Prescribe by brand name.  So far no concerns.

VEDOLIZUMAB – vs gut-tropic lymphocyte migration.  Approved in adults.

20% Crohns don’t get change in bloods with acute exacerbations!  Check stool cultures and C diff, can start EEN pending results.

See Ulcerative Colitis.

Prognosis

Mean final height in CD 2.4cm below target.

Transition only when completed growth and development and without education/psych issues.

SSPGHAN guidelines 2014

Food protein–induced enterocolitis syndrome (FPIES)

Allergy, Gastro, General paediatrics, Immunology, Neonatology, Nutrition

Non–IgE-mediated severe gastrointestinal food hypersensitivity, typically presents in early infancy with repeated vomiting, dehydration, lethargy, metabolic acidosis (even mimicking sepsis).  Watery diarrhoea (sometimes with blood and/or mucus) can develop in some cases. The severity is really what makes it worthy of a distinct name, debatable if it is actually distinct from other non-IgE mediated food allergy.

Probably underdiagnosed.

A few unusual features cf type 1 allergy.

The most common offending foods are cow’s milk and soy in young infants; in older infants, there are a range of food triggers including some foods usually not considered allergenic eg rice, oat, chicken, sweet potato!  Egg an unusual cause in some countries!  Cases in breastfed infants have been reported, even severe hypotension requiring intensive care.

Acute symptoms occur 1 to 5 hours after ingesting the offending food.  Lasts up to 24 hours. Not always consistent, which might suggest co-factors important.

In Europe, rare to get multiple food FPIES but in UK/US/Australia about 25% (English speaking!?).

Diagnosis

Diagnosis is based, predictably for a non-IgE condition, on clinical history and food challenges. Leucocytosis and methaemoglobinaemia are associated but low specificity/sensitivity.  

2017 Consensus out of date but diagnostic criteria still used – 

  • Major – vomiting at 1-4 hours in absence of type 1 skin/resp symptoms.
  • Minor – at least 3 minor criteria eg second episode of repetitive vomiting after same food; extreme lethargy; hypotension; need for hospital care or IV fluids; etc

Probably mild, mod and severe! Proposed BIO-FPIES criteria includes abdominal pain, nausea, increase in neutrophil count (but 3 points for second episode of repetitive vomiting after same food).

Phenotype switching

Egg and nut FPIES often go on to develop IgE sensitisation (about 20%), less for others. Of those, about 30% of milk FPIES will switch to type 1 phenotype, 15% for egg, less for other foods. But overall, unlikely to make much of a difference to care (and doesn’t help predict resolution).

Management

No role for antihistamine/adrenaline!

BSACI has FPIES plan.

Family support at www.fpiesuk.org.

For introducing weaning foods, when known FPIES to one food, start with low risk foods, supervise common triggers eg rice/egg.

Challenge

Challenge is necessary to decide whether things are getting better or not. Consensus is that 12-18 months after last reaction is a good balance between chances of things being better, and risk of causing severe reaction.  

50% milk/soya resolve by age 3-4, more like 4-5 years for other foods. 

Traditional protocol is 0.3g/kg protein, divided into 3 doses over 30 mins.  But unrealistic for low protein foods eg fruit. And doesn’t really make sense to split dose when you don’t expect a reaction for hours (but risk of switch to type 1 allergy for egg/nuts).

2 day protocol (25% portion then whole portion next day) had less severe reactions. 

25-30% of age appropriate portion triggers reaction in most children. [Baked???] Over 50% react after at least 2 hours. 

Beaudoin 2024 has home challenge protocol but brave… 

[Marta Vazquez-Ortiz systematic review]

[BSACI FPIES grand round – Marta Vazquez-Ortiz (Imperial/St Mary’s, BIO-FPIES research network)] [2025 Shaker shared decision making] [2024 Anvari]

Alpha 1 Antitrypsin deficiency

Gastro, General paediatrics, Genetics, Respiratory,

Similar incidence to CF in white populations. Protease inhibitor (PI), counteracts neutrophil elastase. Alleles include PiZ (defective), PiM (normal), PiNull (non functioning). Protein phenotype then described as Z, M, MZ, or None

  • Double Null – very high risk of COPD but no liver disease!
  • ZZ have high risk of COPD and liver disease.
  • SZ also seen, risk of COPD.

The risk of emphysema is increased in males, in asthma and especially in smokers.

PiMZ genotype does not appear to predispose to chronic liver disease (in case control study). On the other hand, patients with decompensated liver disease (of any cause) were significantly more likely to have PiMZ, and particularly in HCV or NAFLD PiMZ was associated with more severe liver disease and need for liver transplantation. Suggests that if you have some other cause for liver disease, PiMZ will do less well.

J Pediatr Gastroenterol Nutr. 2006 Jul;43 Suppl 1:S30-5. [pmid:16819398]

About 10% of children with Z phenotype have prolonged (obstructive) jaundice as babies, most have abnormal LFTs at some point in first year of life. Only 2% progress to liver failure requiring transplantation, however. Risk of hepatocellular carcinoma higher, not surprisingly.

Augmentation therapy with IV AAT approved by FDA, expensive. May slow decline in lung function but not great evidence yet. No intended to treat liver disease.

Screening is really only useful in aggressive smoking and alcohol advice. Non-alcoholic fatty liver disease seems to worsen other causes of liver disease so avoidance of obesity seems important too.

Necrotizing panniculitis associated with AAT deficiency, seems to respond rapidly to AAT treatment.

 

Ulcerative Colitis

Gastro, General paediatrics

About a third of IBD in kids, incidence stable unlike Crohn’s.

Associated with autoimmune disease especially sclerosing cholangitis.
80% kids have pancolitis (cf 20% adults), otherwise proctitis alone or
other local disease.

Acute Severe Colitis

“About saving lives, not saving colons”.

15% severe at presentation, 28% have at some point in childhood.

The first attack of colitis tends to be more severe and disease more
extensive in children than in adults. Many respond to conventional
medical therapy but 8-30% at 1 year will have undergone colectomy for
failed medical treatment (depending on disease severity).

Acute severe colitis is characterised by greater than 6 bloody stools
per day, abdominal tenderness, fever, anaemia, leucocytosis, and
hypoalbuminaemia. This is a typical presentation of ulcerative colitis
or may occur as an exacerbation, but the differential includes:

  • Infectious colitis eg Shigella, E. coli O157
  • Crohn’s colitis
  • pseudomembranous colitis
  • ischaemic colitis

Equivalent to PUCAI >65. Moderate colitis 35-60.  Day 3 PUCAI already predictive of future colectomy, second line therapy.

Clostridioides prev Clostridium difficile- less in kids than adults.  Intermittent shedding so multiple samples required.

CMV colitis – not always immunosuppressed.  But no evidence for treatment or prophylaxis…

1-1.5mg/kg max 60mg IVMP.  If toxic or colonic dilatation then NBM, antibiotics, surgical opinion.

Day 3 under 35 PUCAI can consider oral steroids (120% IV dose).  Over 45 refer tertiary centre, screen for second line therapy, start involving surgeons/stoma therapist, sigmoidoscopy (safer than full colonscopy), check HBV/HCV/TB for starting ANti TNF Rx.

Day 5 over 65 start second line (infliximab).  “Sponge, sieve, shark”.  Dose, timing?  Sponge soaks up Abs.  Shark is immune system removing Ab.  Sieve – leaking Ab?  Not much evidence yet!

No response at day 11 consider colectomy.

Alternative second Rx are ciclosporin, tacrolimus.

Toxic megacolon – pain, distension.  Signs less if already on steroids.  Amp, gent, metro.  40mm under 10, 56mm otherwise.

Thrombosis – recognized risk of stroke.  Consider 3+/12 treatment prophylaxis eg OCP, FH

No evidence for bowel rest!

Number of stools can be over estimated if very close episodes. Some may conceal or underestimate number/blood.

Investigations

  • FBC, coag
  • Group and save – consider Cross match esp if possibly for surgery
  • CRP, ESR
  • U&Es, LFTs, Ca – hypokalaemia can precipitate toxic megacolon
  • Blood culture, stool cultures, stool microscopy, C diff toxin
  • CMV serology if immunocompromised
  • AXR – toxic megacolon = 5.5cm+ dilatation

These also used for monitoring, in addition to PUCAI score, a clinical score:

  • abdominal pain (can be ignored or not),
  • rectal bleeding (some stools, most stools, more blood than stool),
  • stool consistency and frequency,
  • nocturnal stooling,
  • activity level (limitation or not).

Under 10 normal, 10-30 mild, 30-60 moderate.  Best averaged over 2 days unless rapidly changing clinically.

Endoscopy is not considered first line investigation given risk of
performation. Limited sigmoidoscopy may give useful information
however.

Management

  • Fluids and nutrition
  • Blood transfusion, esp if Hb<8 or <10 and symptomatic
  • Consider antibiotics (IV Cef and met) if high risk of infection or pre-surgery
  • Stop aminosalicylates until improving
  • Steroids – Hydrocortisone 10mg/kg in 4 divided doses, max 400mg/d else Methylprednisolone 1mg/kg, max 60mg. Do not delay pending microbiology!
  • TED stockings, LMWH
  • Surgical review

Joint medical/surgical care is appropriate. If surgery is likely to be
needed, a stoma nurse would be useful. PUCAI >45 on day 3 suggests
failure to respond (30-70%, depending on severity). Cyclosporin and
Infliximab are second line.

Maintenance

Azathioprine and 6MP are useful for maintenance, less useful acutely
given delayed onset of action. TPMT deficiency predicts myelotoxicity
(use lower doses). 6MP has less side effects (nausea, vomiting,
headache, fatigue). prob best for younger kids.

Sulphasal liquid, various granule products for older kids.

Mesalazine enemas good but low acceptability.

[Richard Hansen 2016]

Hirschsprung’s disease

Gastro, General paediatrics, Neonatology, Surgical

Congenital absence of ganglion cells in distal bowel, beginning at the internal sphincter and extending proximally.  Fails to relax, hence functional obstruction.  Mostly present as neonates, with delayed meconium and abdo distension, else mostly under 2yr with intractable constipation, failure to thrive, repeated vomiting. Rarely soiling! 1/3 of these later presenting patients present with enterocolitis, with fever, shock, bloody stools.  Probably due to abnormal colonic mucosa, a problem that seems to persist even after surgery.

Some series describe patients without symptoms in neonatal/infancy period!

1 in 5000 births. 4:1 males:females.  FH 30%. Assoc with downs, cong deafness.

Empty rectum on AXR (ie gas pattern disappears)! [insert axr] May be forceful expulsion at PR (which may also spoil diagnostic value of barium or manometry studies). Barium enema can be useful but high false neg in first 3/12, and need to avoid PR examination and enemas for preceding 48hr else distal narrowing lost.

Treatment – resection of affected segment.  Postop do well, risk of anal hypertonicity (enterocoitis), stricture.